When Google's Gmail crashed for a few hours on Sept. 1, the Internet lit up with complaints and panicked instant messages. People sure do expect a lot from their free services. But the outage raised some interesting questions about the reliability of the kinds of free, cloud-based apps that organizations are turning to in droves as ways to move more of their operations online while saving money at the same time. Is it always the right move?

Fortune's Jessi Hempel writes that more than 1.75 million companies pay an annual $50-per-user subscription fee for their employees to use Google Apps, including Gmail. Should they expect 100 percent uptime? It's not that traditional e-mail services are any more reliable than services managed from the cloud," says Hempel. "In fact, most e-mail goes down. According to Osterman Research, based in Black Diamond, Wash., e-mail systems in mid-size and large organizations have a mean of 53 minutes of unplanned down time in a typical month. Add that up and it becomes 10.6 hours annually. By contrast, observers point out that Gmail has crashed only a few times this year.

Still, this little glitch does raise big questions about how and when "cloud computing" should be deployed within organizations that demand 24/7 fault-free performance of mission-critical apps such as e-mail. Have you embraced cloud computing concepts yet? To what extent do you trust them? Good questions to ponder as this trend rolls on.

-- Don Willmott